Integral rubber lampholder



March 10, 1970 L. L SHROYER INTEGRAL RUBBER LAMPHOLDER 2 Sheets-Sheet 1 Filed Feb. 16. 1968 INVENTOR LARRY L.SHROYER BY M Zfimy ATTORNEYS March 10, 1970 L. SHROYER 3,500,294

INTEGRAL RUBBER LAMPHOLDER Filed Feb. 16, 1968 2 Sheets-Sheet 2 INVENTOR LARRY I... SHROYER BY 44 a ATTORNEYS United States Patent Office 3,500,294 Patented Mar. 10, 1970 3,500,294 INTEGRAL RUBBER LAMPHOLDER Larry L. Shroyer, Wolcottville, Ind., assignor to Lyall Electric, Inc., Albion, Did, a corporation of Indiana Filed Feb. 16, 1968, Ser. No. 706,024 Int. Cl. H01r 31/06, 33/94 US. Cl. 339-170 7 Claims ABSTRACT OF THE DISCLOSURE A lampholder is molded of rubber as an internal structure having threads for receiving a lamp base and having grooves and slots for receiving contact terminals. The contact terminals are inserted into the slots and held by the cooperating configuration of the grooves, slots, and con tact terminals.

BACKGROUND OF THE INVENTION My invention relates to an improved rubber lampholder, and particularly to such a lampholder that can be integrally molded as a unit and provided with contact terminals which are held in the lampholder by the configuration of the lampholder and the terminals.

Presently available lampholders utilize an insulating member which holds a threaded metal shell and a bottom contact for engaging the terminals of an electric lamp. The metal shell, the contact, and the insulating member are assembled and held by fastening members such as screws, rivets, various washers, and other hardware. While such a lampholder functions well under ordinary conditions, it has several disadvantages. The assembly or manufacture of such a lampholder is time consuming and relatively expensive because of the number of parts needed for the lampholder. The threaded metal shell is usually ruined if the lampholder is dented or crushed. The various members increase the chance for an electrical path to become open circuited or short circuited. And, the various contacts and metals used in the lampholder are subjcct to corrosion and resultant failure or high resistance.

Accordingly, an object of my invention is to provide an improved lampholder which is relatively simple in construction.

Another object of my invention is to provide an improved integral lampholder which permits each terminal to be integral and inserted and held in the lampholder without fastening members or operations.

Another object of my invention is to provide an improved molded rubber lampholder which is relatively free from failure resulting from crushing or impact.

Another object of my invention is to provide an improved lampholder which has relatively few parts and which is therefore relatively easy and inexpensive to manufacture.

Another object of my invention is to provide an improved lampholder which, because of its relatively simple construction, is less subject to failure from corrosion and moisture.

Another object of my invention is to provide an improved lampholder which has relatively wide spacing between the terminals, and which therefore has better insulating characteristics.

SUMMARY OF THE INVENTION Briefly, these and other objects are achieved in accordance with my invention by a lampholder formed of an integral member of electrically insulating material such as rubber. The member has a cylindrical opening extending from one end along a central longitudinal axis toward the other end. The cylindrical opening has threads around its sides to receive the threads of a lamp base, and has a substantially fiat bottom spaced from the other end of the member. The member has a rectangular groove that extends parallel to the central longitudinal axis along the threads from a starting point near the one end toward the bottom. An integral metallic side contact having a rectangular cross section is positioned in the rectangular groove and slot. In a first embodiment, the side contact extends through a slot in the bottom beyond the other end of the member to form a terminal, and is held by a retaining slot. In a second embodiment, the side contact extends through a slot in the side to form a terminal, and is held by a tang. An integral metallic bottom contact having a rectangular cross section is positioned at the bottom of the member. In the first embodiment, the bottom contact extends through a slot in the bottom beyond the other end of the member to form a terminal, and is held by a tang. In the second embodiment, the bottom contact extends through a slot in the side to form a terminal, and is held by a tang. The contacts are easily inserted and held in the member. Thus, I provide a lampholder which can be integrally molded with all necessary configurations, and which can be easily provided with the necessary contacts and terminals. The integrally molded insulating members resists being damaged, and the integral contacts and terminals. provide greater spacing and better insulating qualities.

BRIEF DESCRIPTION OF THE DRAWING The subject matter which I regard as my invention is particularly pointed out and distinctly claimed in the claims. The structure and operation of my invention, together with further objects and advantages, may be better understood from the following description given in connection with the accompanying drawing, in which:

FIGURE 1 shows a perspective view of a first embodiment of a lampholder in accordance with my invention, with a portion of the lampholder broken away to show its internal construction and with the two terminals removed from the lampholder;

FIGURE 2 shows a longitudinal cross sectional view of the lampholder of FIGURE 1 with the terminals inserted in the lampholder;

FIGURE 3 shows a perspective view of a second embodiment of a lampholder in accordance with my invention, with a portion of the lampholder broken away to show its internal construction and with the two terminals removed from the lampholder; and

FIGURE 4 shows a longitudinal cross sectional view of the lampholder in FIGURE 3 with the terminals inserted in the lampholder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawing, I have shown two lampholders constructed in accordance with my invention but without exterior retaining structures. However, it is to be understood that the outside or exterior of my lampholders may be formed with any desired retaining grommets, flanges, and webs, depending upon the exact application of the lampholder. FIGURES 1 and 2 show a lampholder member 10 with terminals extending beyond the bottom of the member 10. The member 10 has a generally cylindrical opening 11 which extends along a central longitudinal axis 18 from one end 12 toward the other end 13, and which terminates at a bottom 16. The cylindrical opening 11 is provided with internal threads 15 around its sides. The threads 15 preferably extend from a point near the one end 12 and terminate at or near the bottom 16. The threads 15 are generally symmetrical or concentric about the central longitudinal axis 18. The threads 15 are dimensioned and shaped to receive the threaded portion of an electrical device such as the base of a conventional incandescent electrio lamp. The member is provided with a side terminal receiving configuration 20 which extends along the side of the member 10 in the threaded portion and along an axis 19 that is generally parallel to the central longitudinal axis 18. The configuration 20 comprises a rectangular groove 21 which extends from a starting point near the upper portion of the threads to the bottom 16, and continues on through the member 10 in the form of a rectangular slot 22. The bottom or outermost surface of the grooves 21 is preferably below the lowest or outermost part of the threads 15. The upper portion of the configuration is provided with a generally rectangular retaining slot 23 which extends from the starting point at an angle relative to the axis 19 into the side of the member 10. The member 10 is also provided with a bottom terminal receiving configuration 25 in the form of a rectangular slot extending from the bottom 16 through the member 10 to the other end 13.

The member 10 as described thus far may be molded in a single molding or casting operation. I prefer that the member 10 be comprised of a suitable electrically insulating, resilient material such as rubber. Material such as rubber provides the necessary insulating qualities, and is able to withstand impact and crushing Without being damaged. After the member 10 is formed, it is provided with electrical contact members or terminals. A side contact terminal is provided from a suitable metal such as brass. The brass is preferably plated with a suitable material to prevent the rubber and brass from chemically reacting and causing corrosion. The terminal 30 has a rectangular cross section, and has an elongated body 31 and a retaining portion 32 extending at an angle (preferably equal to the angle of the retaining slot 23) along the body 31 toward the other end. The side contact terminal 30 is also provided with a retaining tang or projection 33 which may be punched into the body 31. A bottom contact terminal is also provided from a suitable metal such as brass, which may also be plated. The bottom contact terminal 40 has a rectangular cross section, and ha an elongated body 41. A bottom contact 42 extends at a right angle from one end. A retaining tang or projection 43 is punched into the body 41. Each of the contact terminals 30, 40 may be easily formed in a single operation that provides the respective retaining tangs 33, 43, the retaining portion 32, and the contact portion 42.

The terminals 30, 40 are easily inserted from the positions shown in FIGURE 1 into their respective receiving configurations 20, 25 of the member 10. The terminal 30 is inserted from the inside of the member 10 so that its body 31 is positioned in the groove 21 and slot 22, its retaining portion 32 is positioned in the retaining slot 23, and its end extending beyond the end 13. The tang 33 retains the contact 30 in the member 10 as shown in FIG- URE 2. Likewise, the terminal 40 is inserted from the inside of the member 10 so that the body 41 extends through the member 10 beyond the other end 13. The tang 43 retains the terminal 40. The contact 42 is preferably positioned'so as to be near or centered along the longitudinal axis 18 for contact by the base terminal of the electric lamp. After being inserted, the exposed parts of the terminals 30, 40 are parallel and correspondingly positioned to be connected to an electrical circuit. When an electric lamp or other device is screwed or threaded into the insulating member 10, its external threads press against and engage the faces or sides of the terminal 30 along the elongated body 31, and its base terminal presses against and engages the contact 42 at the bottom 16. Suitable connections may be made to the outer ends of the terminals 30, 40.

FIGURES 3 and 4 show a lampholder member 50 with terminals extending beyond the side of the member 50. The member 50 has a generally cylindrical opening 51 which extends along a central longitudinal axis 58 from one end 52 toward the other end 53, and which terminates at a bottom 56. The cylindrical opening 51 is provided with internal threads 55 around its sides. The threads 55 preferably extend from a point near the one end 52 and terminate at or near the bottom 56. The threads 55 are generally symmetrical or concentric about the central longitudinal axis 58. The threads 55 are dimensioned and shaped to receive the threaded portion of an electrical device such as the base of a conventional incandescent electric lamp. The member 50 is provided With a side terminal receiving configuration 60 which extends along the side of the member 50 in the threaded portion and along an axis 59 that is generally parallel to the central longitudinal axis 58. The configuration 60 comprises a rectangular groove 61 which extends from a starting point near the upper portion of the threads 55 toward, but short of, the bottom 56. At the upper or starting point of the groove 61, a rectangular slot 62 extends radially outward through the side of the member 50. The member 50 is also provided with a bottom terminal receiving configuration 65 which comprises a rectangular groove '66 which starts beneath an overhang portion 67 in the bottom 56, and across the bottom 56. The groove 66 continues through the side of the member 50 as a rectangular slot 68 which is preferably beneath the slot 62.

The member 50 as described thus far may be molded in the same manner and of the same material as described in connection with the member 10. After the member 50 is formed, it is provided with electrical contact members or terminals. A side contact terminal 70 is provided from a suitable metal such as brass, which may be plated. The terminal 70 has a rectangular cross section, and is bent at a right angle to form a contact portion 71 and a tenninal portion 72. The side contact terminal 70 is also provided with a retaining tang or projection 73 which may be punched into the terminal portion 72. A bottom contact terminal is also provided from a suitable metal such as brass, which may be plated. The bottom contact terminal 80 has a rectangular cross section, and is in the form of an elongated body having a retaining tang or projection 81 punched into it. Each of the contact terminals 70, 80 may be easily formed in a single operation that provides the respective retaining tangs 73, 81, and the bend in the terminal 70 that forms the respective contact portion 71 and terminal portion 72.

The terminals 70, 80 are easily inserted from the position shown in FIGURE 3 into their respective receiving configurations 60, 65 of the member 50. The terminal 70 is inserted from the inside of the member 50 so that the contact portion 71 is positioned in the groove 61, and the terminal portion 72 is positioned in the slot 62 and extends beyond the outside of the member 50. The tang 73 retains the terminal 70 in the member 50 as shown in FIGURE 4. The terminal 80 is inserted from the outside of the member 50 so that the inserted end of the terminal 80 is positioned beneath the overhang 67, the portion between the inserted end and the tang 81 is positioned in the rectangular groove 66, and the other portion is positioned in the rectangular slot 68 and extends beyond the outside of the member 50. The tang 81 retains the terminal 80 in the member 50 as shown in FIGURE 4. When an electric lamp or other device is screwed or threaded into the member 50, its external threads press against and engage the faces or sides of the terminal 70 along its contact portion 71, and its base terminal presses against and engages the terminal 80. After being inserted, the exposed parts of the terminals 70, 80 are parallel and correspondingly positioned to be connected to an electric circuit. In FIGURE 4, it will be noted that the terminals 70, 80 are firmly held and that there is very little chance of their engaging or contacting each other. If the terminal 70 tends to pivot, its lower end moves away from the terminal 80. The terminal 80 is securely held in the rectangular slot 68 and beneath the overhang 67, so that it cannot come loose or engage the'terminal 70.

It will thus be seen that my improved lampholder has a relatively simple construction which can be molded or cast in a single operation, and which can be easily provided with the necessary contacts or terminals for external connection. The simple construction of my lampholder eliminates all of the parts such as washers, rivets, and screws, and the necessary assembly of these parts. After my member is molded or cast, the contacts or terminals are easily and quickly inserted. Since my contacts and terminals are simple and integral, they have greater spacing and provide better insulating qualities. The use of only simple plated metal terminals reduces the possibility of corrosion. The use of only a relatively soft material such as rubber without a threaded metal shell permits the lampholder to be struck or crushed, after which it returns to its normal shape without damage. I have found that rubber provides the necessary minimum strength, namely 20 inch-pounds of torque and 20 pounds of pull-out pressure. This strength and also the contact pressure can be controlled by the hardness of the rubber forming the lampholder, and by the relative dimensions of the side terminals and their receiving configurations. If the side terminals are made to project farther into the opening (i.e. nearer the central longitudinal axis), the strength and contact pressure between the holder and the side terminals and between the threaded base of the incandescent lamp are increased.

While I have shown only one embodiment of my lampholder, persons skilled in the art will appreciate that modifications may be made. For example, any threaded electrical device of the proper size may be screwed into the lampholder. The terminals may have threaded openings at their ends to receive screws for threadedly fastening wires to the terminals. However, I prefer that the terminals have the configurations shown to receive a female type connecting plug. The base contacts may also have other configuration, and may be made larger or smaller, depending on the configuration of the lamp to be threaded into the member. Further, an additional contact may be positioned in the bottom for a three-way lamp. Also, any electrical device having a threaded member may be used in my lampholder. Therefore, while my invention has been described with reference to particular embodiments, it is to be understood that modifications may be made without departing from the spirit of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An improved holder for incandescent electric lamps and the like having a threaded base, comprising:

(a) an integral rubber member having a generally cylindrical opening symmertically positioned about a central longitudinal axis and extending from one end of said member toward the other end of said member, said opening having internal threads around the sides thereof for threadedly receiving the threaded base of an electric lamp and terminating in a generally flat bottom;

(b) said rubber member further having a rectangular groove extending along one side parallel to said longitudinal axis from a point near said one end of said member to said bottom, a first rectangular slot extending parallel to said longitudinal axis from said bottom to said other end of said member to form a coincident extension of said rectangular slot extending from said point toward said other end of said member partly into said one side;

(0) said rubber member further having a third rectangular slot extending parallel to said longitudinal axis from said bottom to said other end of said member;

(d) a first metallic terminal having an elongated body that has a rectangular cross section that is substantially identical to said rectangular groove and that has an angular retaining portion extending from one end at an angle relative to said elongated body, said first terminal being positioned in said member with said elongated body in said rectangular groove and in said first rectangular slot with said one end of said first terminal being positioned at said point, with said angular retaining portion being positioned in said second rectangular slot, and with the other end of said terminal extending beyond said other end of said member, said first metallic terminal being arranged to engage the threaded portion of said lamp;

(e) and a second metallic terminal substantially parallel to said first terminal having an elongated body that has a rectangular cross section that is substantially identical to said third rectangular slot and that has a contact portion extending from one end of said second terminal at substantially a right angle relative to said elongated body of said second terminal, said second terminal being positioned in said member with said elongated body in said third rectangular slot with said contact portion resting on said bottom of said member and with the other end of said third terminal extending beyond said other end of said member, said contact portion of said second terminal being arranged to engage the base portion of said lamp.

2. The improved holder of claim 1 wherein at least one of said terminals has a projecting tang that engages the outer surface of said other end of said member for retaining said terminal in its slot.

3. An improved holder for incandescent electric lamps and the like having a threaded base, comprising:

(a) an integral rubber member having a generally cylindrical opening symmetrically positioned about a central longitudinal axis and extending from one end of said member toward the other end of said member, said opening having internal threads around the sides thereof for threadedly receiving the threaded receiving the threaded base of an electric lamp and terminating in a generally fiat bottom;

(b) said rubber member further having a first rectangular groove extending along one side parallel to said longitudinal axis from a point near said one end of said member toward said bottom, and a first rectangular slot extending from said point through the side of said member to the outside of said member;

(c) said rubber member further having a second rectangular groove positioned in said bottom and extending from one side toward the opposite side, a second rectangular slot extending parallel to said second rectangular groove through said one side to the outside of said member to form an extension of said second rectangular groove, and an overhang at the other end of said second rectangular groove;

(d) a first metallic terminal having an elongated body that has a rectangular cross section that is substantially identical to said first rectangular groove and that is bent at substantially a right angle to form a contact portion and a terminal portion, said first terminal being positioned in said member with said contact portion in said first rectangular groove and with said terminal portion extending through said first rectangular slot and extending beyond the outside of said member, said first metallic terminal being arranged to engage the threaded portion of said lamp;

(e) and a second metallic terminal having an elongated body that has a rectangular cross section that is substantially identical to said second rectangular groove, said second terminal being positioned in saidmember with a portion of its elongated body in said second rectangular groove and beneath said overhang portion and with the other end of said second terminal extending through said second rectangular slot and beyond the outside of said member, said second metallic terminal being arranged to engage the base portion of said lamp.

4. The improved holder of claim 3 wherein each of said terminals has a projecting tang that engages a por- 7 tion of said member for retaining said terminals in said member.

5. The improved holder of claim 3 wherein said first terminal has a projecting tang in its outer portion and wherein said second terminal has a projecting tang in its inner portion.

6. An improved holder for an electric lamp having a threaded base that provides at least two terminals, comprising:

(a) an integral member formed of electric insulating material;

(b) said member having a generally cylindrical opening extending from one end of said member along a central longitudinal axis toward the other end of said member;

() said cylindrical opening having internal threads around its sides to receive the threads of a lamp base and having a substantially flat bottom spaced fro-m said other end of said member;

((1) said member having a side terminal receiving configuration extending along an outer axis spaced from and parallel to said central longitudinal axis;

(e) said side terminal receiving configuration having a first rectangular groove extending along said threads from a point near said one end of said member toward said bottom, and a first rectangular retaining slot extending at substantially a right angle relative said first groove from said point through the side of said member to the exterior thereof;

(f) said member having at least one bottom terminal receiving configuration extending along the bottom of said member;

(g) said bottom terminal receiving configuration having a second rectangular groove extending along said bottom substantially thereacross, said bottom of said member providing an overhanging portion at one end of said second rectangular groove, and said member having a second rectangular slot extending from the other end of said second rectangular groove through the side of said member to the exterior thereof;

(h) a metallic side terminal having a rectangular cross section and comprising a contact portion and a terminal portion joined at substantially a right angle, and a retaining tang on said terminal portion;

(i) said side terminal being mounted in said side terminal receiving configuration of said member with said contact portion positioned in said first rectangular groove for engaging the threads of a lamp base, and with said terminal portion of said side terminal extending through said first rectangular slot and extending beyond the outer side of said member with said retaining tang positioned against the outer side of said member;

(j) a metallic bottom terminal having a rectangular cross section and comprising an elongated portion that provides a contact portion and a terminal portion, and a retaining tank between said contact and terminal portions;

(k) and said bottom terminal being mounted in said bottom terminal receiving configuration of said member for engaging the bottom of an electric lamp with said contact portion positioned in said second rectangular slot and partially beneath said overhanging portion, with said retaining tang against the inner wall of said member, and with said terminal portion extending through said second rectangular slot beyond the outer side of said member.

7. The improved holder of claim 6 wherein said terminal portion of said side terminal and said terminal portion of said bottom terminal are positioned side by side in parallel relation when mounted.

References Cited UNITED STATES PATENTS 2,975,392 3/1961 Ludwig 334-199 X 3,019,407 1/1962 Donsky 339- FOREIGN PATENTS 878,050 9/ 1961 Great Britain.

DAVID J. WILLIAMOWSKY, Primary Examiner P. C. KANNAN, Assistant Examiner &3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 50() 294 Dated March 10 1970 Inventor(s) Larry L. Shroyer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 11 "internal" should be integral Column 5, line 63, "groove and a second rectangular" omitted between "rectangular" and "slot" Column 6, line 36, (Claim 3), delete "receiving the threaded" Signed and sealed this 28th day of July 1970.

(SEAL) Attest:

EDWARD M.FLETHER,JR. WILLIAM E. SCHUYLER, JR. Attestlng Officer Commissioner of Patents 

